(Editor's note: This story has been changed since it was first published. Dr. Chuck Murry's name was originally misspelled.)

The University of Washington has been awarded $10 million by the federal government for a five-year program intended to advance basic research on human embryonic stem cells.

"We need to understand what it is that makes these cells tick," said Dr. Chuck Murry, a UW scientist who reported in the September issue of the journal Nature Biotechnology on his lab's success in regenerating damaged hearts in rats using embryonic stem cells.

Stem cell research is one of the hottest arenas in biomedical research because of the potential for using stem cells to rebuild damaged tissue or grow new tissue. Embryonic stem cells, cells taken from an early stage in an organism's development, are "pluripotent" -- meaning they can grow into brain, heart, bone, blood or any other kind of cell.

The UW grant from the National Institutes of Health restricts the university to using the funding for research only on the 21 human embryonic stem cell lines approved for scientific study by President Bush in August 2001.

Bush allowed the use of existing human embryonic stem cells but prohibited federally funded scientists from creating any new lines of stem cells. The president's decision was an attempt to strike a balance between the needs of science and opposition by religious organizations that believe human life begins at conception.

Most scientists believe that the federal limits imposed on human stem cell research will undermine the nation's leadership in biomedical science.

Murry agreed, saying that it will become increasingly difficult to "push the envelope" in stem cell science if the government continues to refuse to fund exploration into any new lines. He and his team collaborated with the California biotechnology firm Geron to do the research using human embryonic stem cells to repair damaged hearts in rats.

Though an encouraging proof of concept, much more research will be needed before the approach can be tried in humans. About 10 percent of the damaged heart muscle was restored by the stem cells, the scientists reported. Murry said new lines of human embryonic stem cells could prove critical to eventually using this to treat heart attack victims.

The $10 million grant to the UW will fund a human embryonic stem cell laboratory and four research projects aimed at deciphering exactly how stem cells are able to renew and differentiate themselves.

The focus at the UW will be on heart and retinal nerve stem cells.

The UW program supplements a nationwide effort, coordinated by the NIH's National Institute of General Medical Sciences, launched in 2003, that is focused on the basic molecular and genetic questions of human embryonic stem cells.